An electrode assembly, a battery, and an electronic device

Abstract

The present disclosure provides an electrode assembly, a battery and an electronic device. The electrode assembly includes a first conductive portion, a second conductive portion and a first metal portion. The first conductive portion includes a first region provided with a conductive substance layer, and a second region apart from the first region; the first metal portion is connected to the second region by welding, and has a third region with a welding trace; the second region has a first end portion and a second end portion when viewed in a first direction perpendicular to a first surface of the first conductive portion; the third region has a third end portion and a fourth end portion; the first metal portion has a fifth end portion in a second direction, and a sixth end portion on the opposite side of the fifth end portion in the second direction and closer to the second end portion than the fifth end portion; a first distance from the third end portion to the fifth end portion is different from a second distance from the fourth end portion to the sixth end portion in the second direction.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of electrochemical devices, and in particular, to an electrode assembly, a battery and an electronic device. BACKGROUND

[0002] Due to the characteristics of high energy density, multiple cycle times and long storage time, lithium ion batteries are widely used in electronic devices such as electric vehicles, electric cars, intelligent storage devices and unmanned aerial vehicles.

[0003] In the related art, when the battery is stored at high temperature, and after the battery is overused, due to the aggravation of the chemical side reaction inside the battery, more gas is generated inside the battery, which causes the battery to have an adverse effect on the product performance of the battery due to the excessively high internal gas pressure. SUMMARY

[0004] The purpose of the embodiments of the present disclosure is to provide an electrode assembly, a battery and an electronic device to reduce the probability of thermal failure of the battery and improve the product performance of the battery.

[0005] The first aspect of the present disclosure provides an electrode assembly, which comprises a first conductive part, a second conductive part and a first metal part. The first conductive part comprises a first region provided with a conductive substance layer and a second region separated from the first region. The first metal part is connected to the second region by welding. The first metal part has a third region with a welding mark. When viewed in a first direction perpendicular to a first surface of the first conductive part, the second region has a first end portion in a second direction perpendicular to the first direction and extending from the first region to the second region, and a second end portion provided on the opposite side of the first end portion in the second direction and farther away from the conductive substance layer than the first end portion. The third region has a third end portion in the second direction, and a fourth end portion provided on the opposite side of the third end portion in the second direction and closer to the second end portion than the third end portion. The first metal part has a fifth end portion in the second direction, and a sixth end portion provided on the opposite side of the fifth end portion in the second direction and closer to the second end portion than the fifth end portion. In the second direction, a first distance from the third end portion to the fifth end portion is not equal to a second distance from the fourth end portion to the sixth end portion.

[0006] The electrode assembly provided by the embodiments of the present disclosure can be connected by welding between the first metal part and the first conductive part, and has a third region at the welding position of the first metal part and the first conductive part, and the third region has welding traces. Since the third end of the third region and the fifth end of the first metal part have a first distance in the second direction, and the fourth end of the third region and the sixth end of the first metal part have a second distance, and the first distance is not equal to the second distance, when the first metal part is welded on the first conductive part, the diffusion speed of the welding residual stress on the fifth end side and the sixth end side of the first metal part is different, and the welding residual stress is easily concentrated on the side with smaller distance between the third region and the first metal part. Therefore, when the internal heat of the battery is high, the side reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, resulting in an increase in internal gas pressure. The larger gas pressure can cause the side with smaller distance between the third region and the first metal part to impact and break, so that the first metal part and the first conductive part are disconnected, realizing the disconnection of the battery, thereby reducing the probability of thermal failure of the battery and improving the life and safety of the battery.

[0007] In addition, the electrode assembly according to the embodiments of the present disclosure can also have the following additional technical features:

[0008] In some embodiments of the present disclosure, the first distance is greater than the second distance. In this way, the side of the first metal part close to the sixth end is easily impacted by the larger gas pressure in the battery to disconnect with the first conductive part, realize the disconnection of the battery, and further improve the product performance of the battery.

[0009] In some embodiments of the present disclosure, the first distance is less than the second distance. In this way, the side of the first metal part close to the fifth end is easily impacted by the larger gas pressure in the battery to disconnect with the first conductive part, realize the disconnection of the battery, and further improve the product performance of the battery.

[0010] In some embodiments of the present disclosure, the first metal part has a seventh end away from the second region and an eighth end opposite to the seventh end in a third direction perpendicular to the second direction; the third region includes a ninth end in the third direction and a tenth end opposite to the ninth end in the third direction and closer to the eighth end than the ninth end when viewed in the first direction; and a third distance from the ninth end to the seventh end is not equal to a fourth distance from the tenth end to the eighth end in the third direction.

[0011] In the third direction, the third region with the welding trace is also not located in the middle of the first metal part, so when the first metal part is welded on the first conductive part, the welding residual stress spreads at different speeds on the seventh end part side and the eighth end part side of the first metal part, and the greater air pressure in the battery can impact the first metal part and the first conductive part to break off on the side with smaller distance in the second direction and the side with smaller distance in the third direction, so as to disconnect the first metal part and the first conductive part, realize the circuit breaking of the battery, and further improve the product performance of the battery.

[0012] Further, the third distance is greater than the fourth distance. In this way, in the third direction, the greater air pressure in the battery is easy to impact the side of the first metal part close to the eighth end part to break off the first conductive part.

[0013] Alternatively, in some other embodiments of the present disclosure, the third distance is smaller than the fourth distance. In this way, in the third direction, the greater air pressure in the battery is easy to impact the side of the first metal part close to the seventh end part to break off the first conductive part, realize the circuit breaking of the battery, and further improve the product performance of the battery.

[0014] In some embodiments of the present disclosure, the second conductive part includes a fourth region provided with a conductive substance layer, and a fifth region away from the fourth region; the electrode assembly further includes a second metal part connected with the fifth region by welding, and the second metal part includes a sixth region with a welding trace; when viewed in a first direction perpendicular to the second surface of the second conductive part, the fifth region has a first side in the second direction and a second side in the second direction opposite to the first side and farther away from the conductive substance layer than the first side; the sixth region has a third side in the second direction and a fourth side in the second direction opposite to the third side and closer to the second side than the third side; the second metal part has a fifth side in the second direction and a sixth side in the second direction opposite to the fifth side and closer to the second side than the fifth side; in the second direction, a fifth distance from the third side to the fifth side is different from a sixth distance from the fourth side to the sixth side.

[0015] The electrode assembly provided by the embodiments of the present disclosure further has a second conductive part and a second metal part, the second metal part is welded to the second conductive part, and the second metal part has a sixth area at the welding position of the second metal part and the second conductive part, and the sixth area has welding traces. When the internal heat of the battery is high, the side reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, which causes the internal gas pressure to increase. The larger gas pressure is easy to cause the side of the sixth area that is far away from the second metal part to be impacted and broken, so that the second metal part is disconnected from the second conductive part, the circuit of the battery is broken, and the probability of thermal failure of the battery is reduced, and the product performance of the battery is improved.

[0016] In some embodiments of the present disclosure, the fifth distance is greater than the sixth distance. In this way, the larger gas pressure in the battery is easy to cause the side of the second metal part that is close to the sixth side to be impacted and disconnected from the second conductive part, so that the circuit of the battery is broken, and the product performance of the battery is further improved.

[0017] In some embodiments of the present disclosure, the fifth distance is less than the sixth distance. In this way, the larger gas pressure in the battery is easy to cause the side of the second metal part that is close to the fifth side to be impacted and disconnected from the second conductive part, so that the circuit of the battery is broken, and the product performance of the battery is further improved.

[0018] In some embodiments of the present disclosure, the second metal part has a seventh side away from the fifth area and an eighth side opposite to the seventh side in a third direction perpendicular to the second direction; the sixth area has a ninth side in the third direction and a tenth side opposite to the ninth side and closer to the eighth side than the ninth side when viewed in the first direction; and the seventh distance from the ninth side to the seventh side is different from the eighth distance from the tenth side to the eighth side in the third direction.

[0019] In the third direction, the sixth area with the welding traces is also not located at the middle position of the second metal part, so that the diffusion speed of the welding residual stress at the seventh side and the eighth side of the second metal part is different after the second metal part is welded to the second conductive part. The larger gas pressure in the battery is easy to cause the side of the sixth area that is far away from the second metal part in the second direction and the side of the sixth area that is far away from the second metal part in the third direction to be impacted and broken, so that the second metal part is disconnected from the second conductive part.

[0020] Further, the seventh distance is greater than the eighth distance. In this way, in the third direction, the larger gas pressure in the battery is easy to cause the side of the second metal part that is close to the eighth side to be impacted and disconnected from the second conductive part, so that the circuit of the battery is broken, and the product performance of the battery is further improved.

[0021] Alternatively, in some other embodiments of the present disclosure, the seventh distance is less than the eighth distance. In this way, in the third direction, a larger air pressure in the battery is prone to impact a side of the second metal part close to the seventh side to disconnect the second metal part from the second conductive part, to realize the disconnection of the battery, and to further improve the product performance of the battery.

[0022] In some embodiments of the present disclosure, in the second direction, a ninth distance from the first end part to the fifth end part is greater than a tenth distance from the second end part to the sixth end part. In the second direction, the first metal part is not at a middle position of the second region. In this way, a larger air pressure in the battery is prone to impact a side of the first metal part close to the second end part to disconnect the first metal part from the first conductive part, to realize the disconnection of the battery, and to further improve the product performance of the battery.

[0023] In some embodiments of the present disclosure, in the second direction, a distance between the first end part and the fifth end part is 1 mm to 30 mm, and a distance between the second end part and the sixth end part is 1 mm to 20 mm. In this way, the first metal part is away from the first end part and the second end part of the first conductive part by a certain distance, thereby being conducive to avoiding the influence of the first conductive part on the first metal part during manufacturing.

[0024] In some embodiments of the present disclosure, in the second direction, an eleventh distance from the first side to the fifth side is less than a twelfth distance from the second side to the sixth side. In this way, welding residual stress on the second metal part is prone to concentrate on a side of the second metal part close to the first side, and a larger air pressure in the battery is prone to impact the side of the second metal part close to the first side to disconnect the second metal part from the second conductive part, to realize the disconnection of the battery, and to further improve the product performance of the battery.

[0025] In some embodiments of the present disclosure, in the second direction, a distance between the first side and the fifth side is 1 mm to 30 mm, and a distance between the second side and the sixth side is 1 mm to 20 mm. In this way, the second metal part is away from the first side and the second side of the second conductive part by a certain distance, thereby being conducive to avoiding the influence of the second conductive part on the second metal part during manufacturing.

[0026] In some embodiments of the present disclosure, in the second direction, a distance between the first end part and the second end part is 10 mm to 40 mm, and a distance between the first side and the second side is 10 mm to 40 mm. In this way, the second region and the fifth region both have sufficient space for accommodating the first metal part and the second metal part, thereby reserving more welding space for the first metal part and the second metal part.

[0027] In some embodiments of the present disclosure, the first conductive part further comprises a seventh region separated from the first region, the seventh region being located on a side of the first region away from the second region. In this way, the first metal part can be selected to be welded to the second region or to the seventh region, so that the first metal part can be located at different positions of the first conductive part, thereby facilitating the improvement of the diversity of the electrode assembly.

[0028] In some embodiments of the present disclosure, the second conductive part further comprises an eighth region separated from the fourth region, the eighth region being located on a side of the fourth region away from the fifth region. In this way, the second metal part can be selected to be welded to the fifth region or to the eighth region, so that the second metal part can be located at different positions of the second conductive part, thereby facilitating the improvement of the diversity of the electrode assembly.

[0029] In some embodiments of the present disclosure, the first conductive part is a positive electrode. The first metal part is connected to the positive electrode to serve as a positive electrode tab.

[0030] In some embodiments of the present disclosure, the second conductive part is a negative electrode. The second metal part is connected to the negative electrode to serve as a negative electrode tab.

[0031] In some embodiments of the present disclosure, the first conductive part is wound around a first axis and comprises a plurality of layers of the first region in the first direction, the second conductive part is wound around the first axis and comprises a plurality of layers of the fourth region in the first direction, the first metal part is connected to the first region located at the outermost side in the first direction, and / or the second metal part is connected to the fourth region located at the outermost side in the first direction. In this way, the first metal part and the second metal part are both located at the outermost side of the electrode assembly, and the pressure at the outermost side is greater than that at other parts of the electrode assembly, thereby facilitating the disconnection of the first metal part from the first conductive part or the disconnection of the second metal part from the second conductive part.

[0032] The second aspect of the present disclosure provides a battery, comprising a shell and the above-mentioned electrode assembly, wherein the electrode assembly is arranged in the shell.

[0033] The battery provided by the embodiments of the present disclosure is beneficial to improve the product performance of the battery by improving the electrode assembly in the battery. The electrode assembly comprises a first conductive part, a second conductive part and a first metal part. The first metal part of the electrode assembly is connected to the first conductive part by welding, and the welding part of the first metal part and the first conductive part has a third region, and the third region has welding marks. Since in the second direction, the third end of the third region and the fifth end of the first metal part have a first distance, the fourth end of the third region and the sixth end of the first metal part have a second distance, and the first distance and the second distance are not equal. Therefore, when the first metal part is welded on the first conductive part, the diffusion speed of the welding residual stress on the fifth end side and the sixth end side of the first metal part is different, and the welding residual stress is easy to concentrate on the side with smaller distance between the third region and the first metal part. Therefore, when the internal heat of the battery is high, the side reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, which leads to an increase in internal gas pressure. The larger gas pressure can cause the side with smaller distance between the third region and the first metal part to impact and break, so that the first metal part and the first conductive part are disconnected, thereby realizing the disconnection of the battery, thereby reducing the probability of thermal failure of the battery and improving the product performance of the battery.

[0034] In addition, the battery according to the embodiments of the present disclosure can also have the following additional technical features:

[0035] In some embodiments of the present disclosure, the material of the shell comprises metal. The shell of metal material is beneficial to protect the internal electrode assembly, thereby improving the reliability of the battery.

[0036] In some embodiments of the present disclosure, the battery is a winding type battery.

[0037] The third aspect of the present disclosure provides an electronic device comprising the battery described above.

[0038] The electronic device provided in this disclosure improves product performance by enhancing the electrode assembly of its battery. The electrode assembly of the electronic device includes a first conductive portion, a second conductive portion, and a first metal portion. The first metal portion of the electrode assembly is welded to the first conductive portion, and a third region with weld marks is present at the weld point. Because there is a first distance between the third end of the third region and the fifth end of the first metal portion, and a second distance between the fourth end of the third region and the sixth end of the first metal portion in the direction from the first region to the second region, and the first and second distances are unequal (i.e., the weld mark is not located in the middle of the first metal portion), when the first metal portion is welded to the first conductive portion, the diffusion rate of residual welding stress differs between the fifth and sixth end sides of the first metal portion. The residual welding stress tends to concentrate on the side with the smaller distance between the third region and the first metal portion. Therefore, when the internal heat of the battery is high, side reactions between the electrolyte and the positive or negative electrode may increase, leading to more gas production and increased internal pressure. Higher air pressure can cause the side of the third region that is closer to the first metal part to break apart, thereby disconnecting the first metal part from the first conductive part and thus breaking the circuit of the battery. This helps to reduce the probability of battery thermal failure and improve the performance of electronic devices. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this disclosure and the prior art, the accompanying drawings used in the embodiments and the prior art are briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other embodiments can be obtained based on these accompanying drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of a wound electrode assembly according to an embodiment of the present disclosure;

[0041] Figure 2 This is a schematic diagram of the structure of the third or sixth region in an embodiment of this disclosure;

[0042] Figure 3 This is a schematic diagram of the unfolded structure of the first conductive part according to an embodiment of this disclosure;

[0043] Figure 4 for Figure 3 Enlarged schematic diagram of region M in the middle;

[0044] Figure 5 This is a schematic diagram of the unfolded structure of the second conductive part according to an embodiment of this disclosure;

[0045] Figure 6 Fig. 1 is a schematic view of a battery according to an embodiment of the present disclosure. Figure 5 Fig. 2 is a schematic view of a battery according to an embodiment of the present disclosure.

[0046] Figure 7 Fig. 3 is a schematic view of a battery according to an embodiment of the present disclosure.

[0047] Reference numerals:

[0048] electronic device-1; battery-10; case-11; separator-12; electrode assembly-100; first conductive portion-110; first region-111; second region-112; third region-113; first surface-1101; second surface-1201; fourth region-114; fifth region-115; sixth region-116; seventh region-117; eighth region-118; first end portion-140; second end portion-141; third end portion-142; fourth end portion-143; fifth end portion-144; sixth end portion-145; seventh end portion-146; eighth end portion-147; ninth end portion-148; tenth end portion-149; first side-160; second side-161; third side-162; fourth side-163; fifth side-164; sixth side-165; seventh side-166; eighth side-167; ninth side-168; tenth side-169; first distance-A; second distance-B; third distance-C; fourth distance-D; fifth distance-E; sixth distance-F; seventh distance-G; eighth distance-H; ninth distance-I; tenth distance-J; eleventh distance-K; twelfth distance-L; second conductive portion-120; first metal portion-130; second metal portion-150. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present disclosure will be described clearly and detailed below. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, but not all the embodiments. Unless otherwise defined, all the technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. The terms used in the specification of the present disclosure are only for the purpose of describing the specific embodiments and are not intended to limit the present disclosure.

[0050] Hereinafter, the embodiments of the present disclosure will be described in detail. However, the present disclosure can be embodied in many different forms, and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0051] Also for purposes of clarity, the dimensions or thicknesses of the various components, layers and / or sections can be exaggerated in the drawings. Throughout this document, the same numbers are used to identify the same components. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. In addition, it should be understood that any reference to something hereinafter "connecting" to something else can mean that such elements are either directly connected to each other or that one or more intermediate elements can be present therebetween.

[0052] Further, the use of "may" when describing embodiments of the present disclosure means that one or more embodiments of the present disclosure "can" include the features and / or functions being described.

[0053] The professional terms used herein are for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0054] Spatially relative terms, such as "on", "above", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device or apparatus in use or operation in addition to the orientations depicted in the figures. For example, if a device or apparatus in the figures is turned over, elements described as "above" other elements or features would then be oriented "below" the other elements or features. Thus, the exemplary term "above" can encompass both an orientation that is above and below. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be later referred to as a second element, component, region, layer or section without departing from the teachings of the exemplary embodiments. In the present disclosure, a first direction can be any one direction in a plane in which a first surface lies.

[0055] Some embodiments of the present disclosure are described in detail below. The following examples and embodiments in the examples can be combined, if not in conflict.

[0056] In the related art, when a battery is stored at a high temperature, and after the battery is overused, due to the aggravation of the chemical side reaction inside the battery, more gas is generated inside the battery, which causes the battery to have an excessively high internal gas pressure, and thus adversely affects the product performance of the battery.

[0057] Embodiments of the present disclosure aim to provide an electrode assembly 100, a battery 10 and an electronic device 1, so as to reduce the probability of thermal failure of the battery 10 and improve the safety of the battery 10.

[0058] As shown in Figure 1 , Figure 3 and Figure 4 , the present disclosure provides a wound electrode assembly 100 in a first aspect. The electrode assembly 100 includes a first conductive part 110, a second conductive part 120 and a first metal part 130. The first conductive part 110 includes a first region 111 provided with a conductive substance layer, and a second region 112 separated from the first region 111. The first metal part 130 is connected to the second region 112 by welding, and the first metal part 130 has a third region 113 with a welding mark. When viewed in a first direction perpendicular to a first surface 1101 of the first conductive part 110, the second region 112 has a first end portion 140 in a second direction perpendicular to the first direction and extending from the first region 111 to the second region 112, and a second end portion 141 provided on the opposite side of the first end portion 140 in the second direction and farther away from the conductive substance layer than the first end portion 140. The third region 113 has a third end portion 142 in the second direction, and a fourth end portion 143 provided on the opposite side of the third end portion 142 in the second direction and closer to the second end portion 141 than the third end portion 142. The first metal part 130 has a fifth end portion 144 in the second direction, and a sixth end portion 145 provided on the opposite side of the fifth end portion 144 in the second direction and closer to the second end portion 141 than the fifth end portion 144. In the second direction, a first distance A from the third end portion 142 to the fifth end portion 144 is not equal to a second distance B from the fourth end portion 143 to the sixth end portion 145.

[0059] The first conductive part 110 and the second conductive part 120 of the electrode assembly 100 of the embodiments of the present disclosure can be positive electrode sheets or negative electrode sheets, and the first conductive part 110 and the second conductive part 120 have opposite polarities. That is, the first conductive part 110 can be a positive electrode sheet or a negative electrode sheet, and correspondingly, the second conductive part 110 can be a negative electrode sheet or a positive electrode sheet, which is not limited by the present disclosure. Further, as shown in Figure 2As shown, the electrode assembly 100 can further include a separator 12 between the first conductive portion 110 and the second conductive portion 120. The separator 12 is used to separate the first conductive portion 110 and the second conductive portion 120 to prevent internal short circuit of the first conductive portion 110 and the second conductive portion 120, and to allow electrolytic ions to pass freely to form a conductive path. The first conductive portion 110 and the second conductive portion 120 can form the electrode assembly 100 in various ways, for example, as shown in the following. Figure 1 As shown, the electrode assembly 100 can further include a separator 12 between the first conductive portion 110 and the second conductive portion 120. Figure 1 As shown, the electrode assembly 100 can further include a separator 12 between the first conductive portion 110 and the second conductive portion 120.

[0060] In the embodiments of the present disclosure, the first direction can be a direction perpendicular to the first surface 1101 of the first conductive portion 110, the second direction can be a direction extending from the first region 111 to the second region 112 of the first conductive portion 110, and the third direction is perpendicular to the first direction and the second direction, respectively. That is, as shown in the following. Figure 1 And Figure 2 As shown, the first direction is the Z-axis direction shown in the figure, the second direction is the X-axis direction shown in the figure, and the third direction is the Y-axis direction shown in the figure.

[0061] In the embodiments of the present disclosure, the first metal portion 130 is a conductive component for leading out the electrode of the first conductive portion 110. The first metal portion 130 can be a positive electrode tab or a negative electrode tab. When the first metal portion 130 is a positive electrode tab, the material of the first metal portion 130 can include at least one of aluminum (Al) or an aluminum alloy, and when the first metal portion 130 is a negative electrode tab, the material of the first metal portion 130 can include at least one of nickel (Ni), copper (Cu), or nickel-plated copper (Ni-Cu).

[0062] The separator 12 can be a porous plastic film, and common materials thereof include polypropylene (PP), polyethylene (PE), and a copolymer of propylene and ethylene, a polyethylene homopolymer, etc.

[0063] In the electrode assembly 100 provided by the embodiments of the present disclosure, the first metal portion 130 is welded to the first conductive portion 110, and the first metal portion 130 and the first conductive portion 110 have a third region 113 at the welding position, and the third region 113 has a welding trace. The third region 113 is located on the first conductive portion 110, and the third region 113 refers to the area of the welding zone formed by the welding of the first conductive portion 110 and the first metal portion 130. The third region 113 can be irregular in shape, or can be a polygon, such as a quadrilateral, a pentagon, etc. In the embodiments of the present disclosure, for ease of understanding, the third region 113 is rectangular. As shown in the following. Figure 2As shown, a structure schematic view of the second region 112 of the first conductive part 110 and the first metal part 130 after welding to form the third region 113. In the welding area, a plurality of welding spots 200 at different positions are included, wherein, in the second direction X, there are a welding spot 201 closest to the first end part 140 and a welding spot 202 farthest from the first end part 140, and two straight lines a and b parallel to the first end part 140 are formed through the welding spot 201 and the welding spot 202 respectively; in the third direction Y, there are a welding spot 203 closest to the seventh end part 146 and a welding spot 204 farthest from the seventh end part 146, and two straight lines c and d parallel to the seventh end part 146 are formed through the welding spot 203 and the welding spot 204 respectively. The straight line a, the straight line b, the straight line c and the straight line d are connected to form the third region 113 described above.

[0064] Since in the direction from the first region 111 to the second region 112, the third end part 142 of the third region 113 is apart from the fifth end part 144 of the first metal part 130 by a first distance A, and the fourth end part 143 of the third region 113 is apart from the sixth end part 145 of the first metal part 130 by a second distance B, and the first distance A is not equal to the second distance B. That is, in the direction from the first region 111 to the second region 112, the third region 113 with welding traces is not located at the middle position of the first metal part 130, that is, the welding traces are not located at the middle position of the first metal part 130. Therefore, after the first metal part 130 is welded on the first conductive part 110, the diffusion speed of the welding residual stress on the fifth end part 144 side and the sixth end part 145 side of the first metal part 130 is different, so that the welding residual stress is more easily concentrated on the side with smaller distance between the third region 113 and the first metal part 130. Therefore, when the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, resulting in an increase in internal gas pressure. The larger gas pressure can cause the side with smaller distance between the third region 113 and the first metal part 130 to be impacted and broken, so as to disconnect the first metal part 130 from the first conductive part 110, thereby achieving the disconnection of the battery 10, thereby facilitating the reduction of the probability of thermal failure of the battery 10 and the improvement of the product performance of the battery 10.

[0065] As shown in FIGS. Figure 3 and Figure 4 In some embodiments of the present disclosure, the first distance A is greater than the second distance B.

[0066] The first distance A refers to the straight-line length along the second direction between the third end 142 of the third region 113 and the fifth end 144 of the first metal part 130. This makes it easier for welding residual stress to concentrate on the side of the first metal part 130 near the sixth end 145. Therefore, when the internal heat of the battery 10 is high, the side reactions between the electrolyte and the positive or negative electrode may increase, resulting in more gas production and increased internal gas pressure. Higher gas pressure can cause the side of the first metal part 130 near the sixth end 145 to break, thereby disconnecting the first metal part 130 from the first conductive part 110, achieving a circuit break in the battery 10, thus reducing the probability of thermal failure in the battery 10 and improving its performance.

[0067] In some other embodiments of this disclosure, the first distance A is smaller than the second distance B. This makes it easier for welding residual stress to concentrate on the side of the first metal portion 130 near the fifth end 144. Therefore, when the internal heat of the battery 10 is high, side reactions between the electrolyte and the positive or negative electrode may increase, leading to the generation of more gas and an increase in internal gas pressure. The higher gas pressure can cause the side of the first metal portion 130 near the fifth end 144 to break off, thereby disconnecting the first metal portion 130 from the first conductive portion 110, achieving a circuit break in the battery 10, which helps reduce the probability of thermal failure in the battery 10 and improves the product performance of the battery 10.

[0068] like Figure 3 and Figure 4 As shown, in some embodiments of this disclosure, the first metal portion 130 has a seventh end 146, which is separated from the second region 112, and an eighth end 147, which is located opposite the seventh end 146 in the third direction perpendicular to the second direction. When viewed along the first direction, the third region 113 includes a ninth end 148 in the third direction and a tenth end 149, which is located opposite the ninth end 148 in the third direction and is closer to the eighth end 147 than the ninth end 148. In the third direction, the third distance C from the ninth end 148 to the seventh end 146 is not equal to the fourth distance D from the tenth end 149 to the eighth end 147.

[0069] In this embodiment of the present disclosure, the third region 113 with welding marks is not located in the middle of the first metal part 130 in the third direction. Therefore, after the first metal part 130 is welded to the first conductive part 110, the diffusion rate of welding residual stress on the seventh end 146 side and the eighth end 147 side of the first metal part 130 is also different. Welding residual stress is easy to concentrate on the side where the distance between the third region 113 and the first metal part 130 is smaller in the second direction and on the side where the distance is smaller in the third direction.

[0070] The size relationship between the third distance C and the fourth distance D in the embodiments of the present disclosure can be flexibly combined with the size relationship between the first distance A and the second distance B, so as to flexibly adjust the position of the area where the welding residual stress is prone to concentrate on the first metal part 130.

[0071] For example, when A > B and C > D, the welding residual stress is prone to concentrate in the intersection area of the two sides of the first metal part 130 close to the sixth end part 145 and close to the eighth end part 147. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, and then more gas is generated, resulting in an increase in the internal gas pressure. When the internal gas pressure is large, the large pressure can cause the intersection area of the two sides of the first metal part 130 close to the sixth end part 145 and close to the eighth end part 147 to impact and break, so as to disconnect the first metal part 130 from the first conductive part 110, realize the circuit breaking of the battery 10, and thus facilitate the reduction of the probability of thermal failure of the battery 10 and the improvement of the product performance of the battery 10.

[0072] Of course, it is easy to understand that when A > B and C < D, the welding residual stress is prone to concentrate in the intersection area of the two sides of the first metal part 130 close to the sixth end part 145 and close to the seventh end part 146. Those skilled in the art can set it according to the needs.

[0073] Further, as shown in Figure 3 and Figure 4 , the third distance C is greater than the fourth distance D. In this way, in the third direction, the welding residual stress is prone to concentrate on one side of the first metal part 130 close to the eighth end part 147. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, and then more gas is generated, resulting in an increase in the internal gas pressure. The large pressure is prone to cause the one side of the first metal part 130 close to the eighth end part 147 to impact and break, so as to disconnect the first metal part 130 from the first conductive part 110, realize the circuit breaking of the battery 10, and thus facilitate the reduction of the probability of thermal failure of the battery 10 and the improvement of the product performance of the battery 10.

[0074] Alternatively, in some other embodiments of the present disclosure, the third distance C is less than the fourth distance D. In this way, in the third direction, the welding residual stress is prone to concentrate on one side of the first metal part 130 close to the seventh end part 146. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, and then more gas is generated, resulting in an increase in the internal gas pressure. The large pressure is prone to cause the one side of the first metal part 130 close to the seventh end part 146 to impact and break, so as to disconnect the first metal part 130 from the first conductive part 110, realize the circuit breaking of the battery 10, and thus facilitate the reduction of the probability of thermal failure of the battery 10 and the improvement of the product performance of the battery 10.

[0075] In some embodiments of the present disclosure, as shown in Figure 1 , Figure 5 and Figure 6 , the second conductive part 120 includes a fourth region 114 provided with a conductive substance layer, and a fifth region 115 separated from the fourth region 114; the electrode assembly 100 further includes a second metal part 150 connected to the fifth region 115 by welding, and the second metal part 150 includes a sixth region 116 having a welding trace; when viewed in a first direction perpendicular to the second surface 1201 of the second conductive part 120, the fifth region 115 has a first side 160 in the second direction and a second side 161 in the second direction opposite to the first side 160 and farther from the conductive substance layer than the first side 160; the sixth region 116 has a third side 162 in the second direction and a fourth side 163 in the second direction opposite to the third side 162 and closer to the second side 161 than the third side 162; the second metal part 150 has a fifth side 164 in the second direction and a sixth side 165 in the second direction opposite to the fifth side 164 and closer to the second side 161 than the fifth side 164; the fifth distance E from the third side 162 to the fifth side 164 is different from the sixth distance F from the fourth side 163 to the sixth side 165 in the second direction.

[0076] The electrode assembly 100 provided by the embodiments of the present disclosure further has a second conductive part 120 and a second metal part 150. The second metal part 150 is a conductive component for leading out the electrode of the second conductive part 120. The second metal part 150 can be a positive electrode tab or a negative electrode tab, and the polarity of the second metal part 150 is opposite to that of the first metal part 130. The material of the second metal part 150 can refer to the related description of the material of the first metal part 130, which will not be described here again.

[0077] In the embodiments of the present disclosure, the second metal part 150 is welded to the second conductive part 120, and the sixth region 116 is provided at the welding position of the second metal part 150 and the second conductive part 120, and the sixth region 116 has a welding trace. The sixth region 116 is located on the second conductive part 120, and the sixth region 116 refers to the region of the welding area formed by the welding of the second conductive part 120 and the second metal part 150. The sixth region 116 can be irregular in shape, or can be a polygon, such as a quadrilateral, a pentagon, etc. In the embodiments of the present disclosure, for the convenience of understanding, the third region 116 is a rectangle. As shown in Figure 2As shown, the fifth region 115 of the second conductive part 120 and the second metal part 150 form the sixth region 116 by welding. In the welding area, there are multiple welding spots 200 at different positions, wherein, in the second direction X, there are a welding spot 201 closest to the first side 160 and a welding spot 202 farthest from the first side 160, and two straight lines a and b parallel to the first side 160 are formed through the welding spot 201 and the welding spot 202 respectively; in the third direction Y, there are a welding spot 203 closest to the seventh side 166 and a welding spot 204 farthest from the seventh side 166, and two straight lines c and d parallel to the seventh side 166 are formed through the welding spot 203 and the welding spot 204 respectively. The straight lines a, b, c and d are connected to form the sixth region 116.

[0078] The second conductive part 120 includes the fourth region 114 and the fifth region 115, and in the direction from the fourth region 114 to the fifth region 115, the third side 162 of the sixth region 116 and the fifth side 164 of the second metal part 150 have a fifth distance E, the fourth side 163 of the sixth region 116 and the sixth side 165 of the second metal part 150 have a sixth distance F, and the fifth distance E is not equal to the sixth distance F. That is, in the direction from the fourth region 114 to the fifth region 115, the sixth region 116 with welding traces is not located at the middle position of the second metal part 150, so when the second metal part 150 is welded on the second conductive part 120, the diffusion speed of welding residual stress at the fifth side 164 and the sixth side 165 of the second metal part 150 is different, and the welding residual stress is easily concentrated on the side with smaller distance between the sixth region 116 and the second metal part 150. When the internal heat of the battery 10 is high, the side-by-side reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, resulting in an increase in internal gas pressure. The larger gas pressure can cause the side of the second metal part 150 close to the sixth side 165 to impact and break, thereby disconnecting the second metal part 150 and the second conductive part 120, achieving the disconnection of the battery 10, thereby reducing the probability of thermal failure of the battery 10 and improving the product performance of the battery 10.

[0079] In some embodiments of the present disclosure, as shown in Figure 5 and Figure 6 The fifth distance E is greater than the sixth distance F. In this way, the welding residual stress is easily concentrated on the side of the second metal part 150 close to the sixth side 165, and when the internal heat of the battery 10 is high, the side-by-side reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, resulting in an increase in internal gas pressure. The larger gas pressure can cause the side of the second metal part 150 close to the sixth side 165 to impact and break, thereby disconnecting the second metal part 150 and the second conductive part 120, achieving the disconnection of the battery 10, thereby reducing the probability of thermal failure of the battery 10 and improving the product performance of the battery 10.

[0080] In some embodiments of the present disclosure, the fifth distance E is smaller than the sixth distance F. In this way, the welding residual stress is prone to concentrate on the side of the second metal part 150 close to the fifth side 164. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, and thus more gas is generated, resulting in an increase in the internal gas pressure. The larger gas pressure can cause the side of the second metal part 150 close to the fifth side 164 to be impacted and broken, so as to disconnect the second metal part 150 from the second conductive part 120, achieve the disconnection of the battery 10, and thus facilitate the reduction of the probability of thermal failure of the battery 10 and the improvement of the product performance of the battery 10.

[0081] In some embodiments of the present disclosure, the second metal part 150 has a seventh side 166 away from the fifth region 115 in a third direction perpendicular to the second direction, and an eighth side 167 opposite to the seventh side 166 in the third direction; the sixth region 116 has a ninth side 168 in the third direction and a tenth side 169 opposite to the ninth side 168 and closer to the eighth side 167 than the ninth side 168 in the third direction when viewed in the first direction. In the third direction, a seventh distance G from the ninth side 168 to the seventh side 166 is different from an eighth distance H from the tenth side 169 to the eighth side 167.

[0082] In the embodiments of the present disclosure, the sixth region 116 with the welding trace is also not located at the middle position of the second metal part 150 in the third direction. Therefore, after the second metal part 150 is welded to the second conductive part 120, the diffusion speeds of the welding residual stress at the seventh side 166 and the eighth side 167 of the second metal part 150 are different, and the welding residual stress is prone to concentrate on the side of the sixth region 116 that is closer to the second metal part 150 in the second direction and the side that is closer to the second metal part 150 in the third direction. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, and thus more gas is generated, resulting in an increase in the internal gas pressure. The larger gas pressure can cause the side of the sixth region 116 that is closer to the second metal part 150 in the second direction and the side that is closer to the second metal part 150 in the third direction to be impacted and broken, so as to disconnect the second metal part 150 from the second conductive part 120, achieve the disconnection of the battery 10, and thus facilitate the reduction of the probability of thermal failure of the battery 10 and the improvement of the product performance of the battery 10.

[0083] Similarly, the size relationship between the fifth distance E and the sixth distance F and the size relationship between the seventh distance G and the eighth distance H of the second conductive part 120 and the second metal part 150 can also be flexibly combined, so as to flexibly adjust the position of the part of the second metal part 150 where the welding residual stress is prone to concentrate.

[0084] Further, asFigure 5 and Figure 6 As shown, the seventh distance G is greater than the eighth distance H. Thus, in the third direction, welding residual stress tends to concentrate on the side of the second metal part 150 closest to the eighth side 167. When the internal heat of the battery 10 is high, the side reactions between the electrolyte and the positive or negative electrode may increase, leading to the generation of more gas and an increase in internal gas pressure. This higher gas pressure makes it easier for the side of the second metal part 150 closest to the eighth side 167 to break, thereby disconnecting the second metal part 150 from the second conductive part 120, achieving a circuit break in the battery 10. This helps reduce the probability of thermal failure in the battery 10 and improves the product performance of the battery 10.

[0085] Alternatively, in some other embodiments of this disclosure, the seventh distance G is less than the eighth distance H. In this way, in the third direction, welding residual stress is more likely to concentrate on the side of the second metal part 150 near the seventh side 166. When the internal heat of the battery 10 is high, the side reactions between the electrolyte and the positive or negative electrode may increase, resulting in more gas production and increased internal pressure. Higher pressure makes it easier for the side of the second metal part 150 near the seventh side 166 to break, thereby disconnecting the second metal part 150 from the second conductive part 120, achieving a circuit break in the battery 10, which helps reduce the probability of thermal failure in the battery 10 and improves the product performance of the battery 10.

[0086] In some embodiments of this disclosure, such as Figure 3 and Figure 4 As shown, in the second direction, the ninth distance I from the first end 140 to the fifth end 144 is greater than the tenth distance J from the second end 141 to the sixth end 145. Thus, residual welding stress on the first metal part 130 is easily concentrated on the side of the first metal part 130 near the second end 141. When the internal heat of the battery 10 is high, the side reactions between the electrolyte and the positive or negative electrode may increase, resulting in more gas production and increased internal gas pressure. Higher gas pressure easily causes the side of the first metal part 130 near the second end 141 to break, thereby disconnecting the first metal part 130 from the first conductive part 110, achieving a circuit break in the battery 10, which helps reduce the probability of thermal failure in the battery 10 and improves the product performance of the battery 10.

[0087] In some embodiments of the present disclosure, in the second direction, the distance between the first end 140 and the fifth end 144 is 1 mm to 30 mm, and the distance between the second end 141 and the sixth end 145 is 1 mm to 20 mm. The first metal part 130 is away from the first end 140 and the second end 141 of the first conductive part 110 by a certain distance, thereby facilitating reduction of the influence of the conductive substance layer on the first metal part 130, and also facilitating avoidance of the influence of the first conductive part 110 on the first metal part 130 during manufacturing, such as during winding.

[0088] In some embodiments of the present disclosure, in the second direction, the eleventh distance K of the first side 160 to the fifth side 164 is less than the twelfth distance L of the second side 161 to the sixth side 165. The welding residual stress on the second metal part 150 is prone to concentrating on the side of the second metal part 150 close to the first side 160. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, thereby generating more gas, resulting in an increase in the internal gas pressure. The larger gas pressure is prone to causing the side of the second metal part 150 close to the first side 160 to be impacted and broken, thereby causing the second metal part 150 to be disconnected from the second conductive part 120, achieving disconnection of the battery 10, and thereby facilitating reduction of the probability of thermal failure of the battery 10 and improvement of the product performance of the battery 10.

[0089] In some embodiments of the present disclosure, in the second direction, the distance between the first side 160 to the fifth side 164 is 1 mm to 30 mm, and the distance between the second side 161 to the sixth side 165 is 1 mm to 20 mm. The second metal part 150 is away from the first side 160 and the second side 161 of the second conductive part 120 by a certain distance, thereby facilitating reduction of the influence of the conductive substance layer on the second metal part 150, and also facilitating avoidance of the influence of the second conductive part 120 on the second metal part 150 during manufacturing.

[0090] In some embodiments of the present disclosure, in the second direction, the distance between the first end 140 and the second end 141 is 10 mm to 40 mm, and the distance between the first side 160 and the second side 161 is 10 mm to 40 mm. The second region 112 and the fifth region 115 each have sufficient space for accommodating the first metal part 130 and the second metal part 150, thereby reserving more welding space for the first metal part 130 and the second metal part 150, and facilitating improvement of the reliability of the battery 10.

[0091] In some embodiments of the present disclosure, as Figure 3As shown, the first conductive part 110 further includes a seventh region 117 which is separated from the first region 111 and is located on the side of the first region 111 away from the second region 112. In this way, the first metal part 130 can be welded to either the second region 112 or the seventh region 117, so that the first metal part 130 can be located at different positions of the first conductive part 110, thereby facilitating the improvement of the diversity of the electrode assembly 100.

[0092] In some embodiments of the present disclosure, as shown in Figure 5 As shown, the second conductive part 120 further includes an eighth region 118 which is separated from the fourth region 114 and is located on the side of the fourth region 114 away from the fifth region 115. In this way, the second metal part 150 can be welded to either the fifth region 115 or the eighth region 118, so that the second metal part 150 can be located at different positions of the second conductive part 120, thereby facilitating the improvement of the diversity of the electrode assembly 100.

[0093] In some embodiments of the present disclosure, the first conductive part 110 is a positive electrode. The first metal part 130 is connected to the positive electrode to serve as a positive electrode tab. At this time, the first metal part 130 is used to lead the positive current of the electrode assembly 100.

[0094] In some embodiments of the present disclosure, the second conductive part 120 is a negative electrode. The second metal part 150 is connected to the negative electrode to serve as a negative electrode tab. At this time, the second metal part 130 is used to lead the negative current of the electrode assembly 100.

[0095] In some embodiments of the present disclosure, the first conductive part 110 is wound around a first axis and includes a plurality of first regions 111 in a first direction, and the second conductive part 120 is wound around the first axis and includes a plurality of fourth regions 114 in the first direction. The first metal part 130 is connected to the first region 111 which is located at the outermost side in the first direction. In this way, the first metal part 130 is located at the outermost side of the electrode assembly 100, and the pressure at the outermost side is greater than that at other parts of the electrode assembly 100, thereby facilitating the disconnection of the first metal part 130 from the first conductive part 110.

[0096] Alternatively, in some other embodiments of the present disclosure, the second metal part 150 is connected to the fourth region 114 which is located at the outermost side in the first direction. In this way, the second metal part 150 is located at the outermost side of the electrode assembly 100, and the pressure at the outermost side is greater than that at other parts of the electrode assembly 100, thereby facilitating the disconnection of the second metal part 150 from the second conductive part 120.

[0097] ​Alternatively, in some other embodiments of the present disclosure, the first metal part 130 is connected with the first region 111 located at the outermost side in the first direction, and the second metal part 150 is connected with the fourth region 114 located at the outermost side in the first direction. In this way, the first metal part 130 and the second metal part 150 are both located at the outermost side of the electrode assembly 100, and the pressure at the outermost side is greater than that at other parts of the electrode assembly 100, so that the first metal part 130 and the first conductive part 110 are easily disconnected or the second metal part 150 and the second conductive part 120 are easily disconnected.

[0098] The second aspect of the present disclosure provides a battery 10, such as Figure 7 as shown, Figure 7 a schematic view of a section of the battery 10 taken along a plane in which Y and Z lie and viewed in the direction of X. The battery 10 includes a case 11 and the above-mentioned electrode assembly 100, and the electrode assembly 100 is disposed in the case 11.

[0099] The case 11 can be a square case or a cylindrical case, and the embodiments of the present disclosure are not limited thereto.

[0100] The battery 10 provided by the embodiments of the present disclosure improves the product performance of the battery 10 by improving the electrode assembly 100 therein. The electrode assembly 100 includes a first conductive portion 110, a second conductive portion 120, and a first metal portion 130. The first metal portion 130 of the electrode assembly 100 is welded to the first conductive portion 110, and has a third region 113 at the welding position of the first metal portion 130 and the first conductive portion 110, and the third region 113 has welding marks therein. In the direction from the first region 111 to the second region 112, the third end 142 of the third region 113 is spaced apart from the fifth end 144 of the first metal portion 130 by a first distance A, the fourth end 143 of the third region 113 is spaced apart from the sixth end 145 of the first metal portion 130 by a second distance B, and the first distance A is different from the second distance B, that is, in the direction from the first region 111 to the second region 112, the third region 113 having the welding marks is not located at the middle position of the first metal portion 130, that is, the welding marks are not located at the middle position of the first metal portion 130, so that when the first metal portion 130 is welded to the first conductive portion 110, the diffusion speed of the welding residual stress on the fifth end 144 side and the sixth end 145 side of the first metal portion 130 is different, and the welding residual stress is easily concentrated on the side between the third region 113 and the first metal portion 130 with a smaller distance. Therefore, when the internal temperature of the battery 10 is high, the side-to-reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, resulting in an increase in the internal gas pressure. The larger pressure can cause the side between the third region 113 and the first metal portion 130 with a smaller distance to be broken, so that the first metal portion 130 is disconnected from the first conductive portion 110, and the battery 10 is disconnected, thereby reducing the probability of thermal failure of the battery 10 and improving the product performance of the battery 10.

[0101] In some embodiments of the present disclosure, the material of the shell 11 includes metal. The shell 11 of the metal material is beneficial to protect the electrode assembly 100 inside, thereby improving the reliability of the battery 10. For example, the material of the shell 11 is aluminum, iron, or aluminum alloy, and the embodiments of the present disclosure are not limited thereto.

[0102] In some embodiments of the present disclosure, the battery 10 is a winding type battery.

[0103] Specifically, a plurality of embodiments and comparative examples are given to more specifically describe the above-mentioned disclosed embodiments. A plurality of batteries composed of different electrode assemblies 100 are selected to perform various experiments, and the experimental results are shown in Table 1:

[0104] Table 1 Influence of welding mark position on battery product performance

[0105]

[0106]

[0107] In Table 1, the high-temperature storage test refers to: the battery is fully charged to 100% SOC, and stored at 85 degrees for 7 days. The high-temperature cycle test refers to: the battery is cycled from zero capacity to full capacity 300 times at an ambient temperature of 60 degrees, with a charge rate of 1.3C and a discharge rate of 1C; wherein the charge rate of 1.3C means that it can be charged 1.3 times in one hour, and the discharge rate of 1C means that it takes 1 hour to complete one discharge; the overcharge test refers to charging the battery at a constant current of 3 times the rated current of the battery, and when the battery voltage reaches 5V, the constant current is reduced to 0.05 times the rated current of the battery.

[0108] The pass rate refers to the ratio of the number of batteries that do not occur thermal failure during the test or after the test to the total number of batteries tested, rather than the ratio of the number of batteries that still have perfect function after the test to the total number of batteries tested. For example, in the high-temperature cycle test, the pass rate of the comparative example is 7 / 20, which means that among the 20 batteries tested, 13 have thermal failure; the pass rate of Example 1 is 20 / 20, which means that among the 20 batteries of the present disclosure, none have thermal failure. This does not mean that all batteries still have perfect function after the test, that is, a portion or even all of the 20 batteries of the present disclosure avoid thermal failure by breaking the first conductive part and the first metal part or the second conductive part and the second metal part, and they no longer have the perfect function of the battery.

[0109] In the battery size, the tab refers to the first metal part 130 or the second metal part 150 in the electrode assembly 100 of the present disclosure; A, B, C, and D refer to the first distance, the second distance, the third distance, and the fourth distance in the present disclosure, respectively.

[0110] In Comparative Example 1, A = B and C = D, which means that the welding mark, i.e., the third region 113, is located in the middle of the first metal part 130 in the second direction and the third direction, so that the diffusion speed of the welding residual stress on both sides of the first metal part 130 is the same. Experimental results show that in the high-temperature storage, high-temperature cycle, and overcharge pass rate tests, there are conditions of battery thermal failure, which is not conducive to improving the product performance of the battery.

[0111] In Example 1, A > B and C > D, which means that Figure 1As shown, the welding mark, i.e., the third region 113, is not located in the middle of the first metal part 130 in the second direction and the third direction. In comparison with the comparative example 1, it is shown that in the high-temperature storage, high-temperature cycle and overcharge pass rate experiments, the battery of the example 1 does not have a thermal failure condition, and the first metal part 130 and the first conductive part 110 are broken, thereby reducing the probability of the battery having a thermal failure condition. That is, in the example 1, the welding residual stress is easily concentrated in the intersection region of the two sides of the first metal part 130 close to the sixth end part 145 and close to the eighth end part 147. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, thereby generating more gas, resulting in an increase in the internal gas pressure. The large gas pressure can cause the intersection region of the two sides of the first metal part 130 close to the sixth end part 145 and close to the eighth end part 147 to impact and break, thereby disconnecting the first metal part 130 and the first conductive part 110, achieving the disconnection of the battery 10, thereby reducing the probability of the battery 10 having a thermal failure condition and improving the product performance of the battery 10.

[0112] In the example 2, A > B and C = D, i.e., the third region 113 is not located in the middle of the first metal part 130 in the second direction and is located in the middle of the first metal part 130 in the third direction. In comparison with the comparative example 1, it is shown that in the high-temperature cycle pass rate experiment, the pass rate of the comparative example 1 is 7 / 20, and the pass rate of the example 2 is 8 / 20. The probability of the example 2 having a battery thermal failure condition is lower than that of the comparative example 1. The first metal part 130 and the first conductive part 110 are broken, thereby reducing the probability of the battery having a thermal failure condition. That is, in the example 2, the welding residual stress is easily concentrated in the side of the first metal part 130 close to the sixth end part 145. When the internal heat of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode can increase, thereby generating more gas, resulting in an increase in the internal gas pressure. The large gas pressure can cause the side of the first metal part 130 close to the sixth end part 145 to impact and break, thereby disconnecting the first metal part 130 and the first conductive part 110, achieving the disconnection of the battery 10, thereby reducing the probability of the battery 10 having a thermal failure condition and improving the product performance of the battery 10.

[0113] The third aspect of the present disclosure provides an electronic device 1, which comprises the above-mentioned battery 10.

[0114] The electronic device can be, but is not limited to, an electric vehicle, a mobile phone, a notebook computer, an electric toy, an electric tool, an electric car, etc., which uses the battery 10 of the second aspect of the present disclosure as a power source.

[0115] The electronic device 1 provided by the embodiments of the present disclosure is advantageous to improve the product performance of the electronic device by improving the electrode assembly 100 of the battery 10. The electrode assembly 100 includes a first conductive part 110, a second conductive part 120 and a first metal part 130. The first metal part 130 of the electrode assembly 100 is welded with the first conductive part 110, and has a third area 113 at the welding position of the first metal part 130 and the first conductive part 110, and the third area 113 has welding traces. In the direction from the first area 111 to the second area 112, the third end 142 of the third area 113 and the fifth end 144 of the first metal part 130 have a first distance A, the fourth end 143 of the third area 113 and the sixth end 145 of the first metal part 130 have a second distance B, and the first distance A is not equal to the second distance B. That is, in the direction from the first area 111 to the second area 112, the third area 113 with welding traces is not located at the middle position of the first metal part 130, that is, the welding traces are not located at the middle position of the first metal part 130. Therefore, after the first metal part 130 is welded on the first conductive part 110, the diffusion speed of the welding residual stress on the fifth end 144 side and the sixth end 145 side of the first metal part 130 is different, and the welding residual stress is easy to concentrate on the side with smaller distance between the third area 113 and the first metal part 130. Therefore, when the internal temperature of the battery 10 is high, the side reaction between the electrolyte and the positive electrode or the negative electrode may increase, and more gas is generated, resulting in an increase in internal gas pressure. The larger gas pressure can cause the side with smaller distance between the third area 113 and the first metal part 130 to impact and break, so that the first metal part 130 and the first conductive part 110 are disconnected, and then the battery 10 is disconnected, thereby being advantageous to reduce the probability of thermal failure of the battery 10, and thereby being advantageous to improve the product performance of the electronic device 1.

[0116] The above only describes the preferred embodiments of the present disclosure, and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. An electrode assembly, comprising a first conductive portion, a second conductive portion, and a first metal portion, wherein: The first conductive portion includes a first region having a conductive material layer, and a second region separated from the first region; The first metal part is connected to the second region by welding, and the first metal part includes a third region with welding marks; When viewed along a first direction perpendicular to the first surface of the first conductive portion, the second region has a first end in a second direction perpendicular to the first direction and extending from the first region to the second region, and a second end located on the opposite side of the first end in the second direction and at a distance from the conductive material layer that is farther than the first end. The third region has a third end in the second direction and a fourth end in the second direction located opposite the third end and closer to the second end than the third end; The first metal portion has a fifth end in the second direction and a sixth end in the second direction located opposite the fifth end and closer to the second end than the fifth end; Along the second direction, the first distance from the third end to the fifth end is not equal to the second distance from the fourth end to the sixth end.

2. The electrode assembly according to claim 1, wherein, The first distance is greater than the second distance.

3. The electrode assembly according to claim 1, wherein, The first distance is less than the second distance.

4. The electrode assembly according to claim 2 or 3, wherein: The first metal portion has a seventh end portion that is separated from the second region in a third direction perpendicular to the second direction, and an eighth end portion that is provided on the opposite side of the seventh end portion in the third direction. When viewed along the first direction, the third region includes a ninth end in the third direction and a tenth end in the third direction located opposite the ninth end and closer to the eighth end than the ninth end; In the third direction, the third distance from the ninth end to the seventh end is not equal to the fourth distance from the tenth end to the eighth end.

5. The electrode assembly according to claim 4, characterized in that, The third distance is greater than the fourth distance.

6. The electrode assembly according to claim 4, characterized in that, The third distance is less than the fourth distance.

7. The electrode assembly according to claim 1, wherein: The second conductive portion includes a fourth region having a conductive material layer, and a fifth region separate from the fourth region; The electrode assembly further includes a second metal part, which is connected to the fifth region by welding. The second metal part includes a sixth region with welding marks. When viewed along the first direction perpendicular to the second surface of the second conductive portion, the fifth region has a first side along the second direction and a second side located on the opposite side of the first side in the second direction and farther away from the conductive material layer than the first side. The sixth region has a third side in the second direction and a fourth side in the second direction located opposite the third side and closer to the second side than the third side; The second metal portion has a fifth side in the second direction and a sixth side in the second direction located opposite the fifth side and closer to the second side than the fifth side; Along the second direction, the fifth distance from the third side to the fifth side is different from the sixth distance from the fourth side to the sixth side.

8. The electrode assembly according to claim 7, wherein, The fifth distance is greater than the sixth distance.

9. The electrode assembly according to claim 7, wherein, The fifth distance is less than the sixth distance.

10. The electrode assembly according to claim 8 or 9, wherein: The second metal part has a seventh side that is separate from the fifth region in a third direction perpendicular to the second direction, and an eighth side that is provided on the opposite side of the seventh side in the third direction. The sixth region, when viewed along the first direction, has a ninth side in the third direction and a tenth side in the third direction, which is located opposite the ninth side and is closer to the eighth side than the ninth side. In the third direction, the seventh distance from the ninth side to the seventh side is not equal to the eighth distance from the tenth side to the eighth side.

11. The electrode assembly of claim 10, wherein, The seventh distance is greater than the eighth distance.

12. The electrode assembly according to claim 10, wherein, The seventh distance is less than the eighth distance.

13. The electrode assembly according to claim 1 or 7, wherein: In the second direction, the ninth distance from the first end to the fifth end is greater than the tenth distance from the second end to the sixth end.

14. The electrode assembly according to claim 1 or 7, wherein, In the second direction, the distance between the first end and the fifth end is 1 mm to 30 mm, and the distance between the second end and the sixth end is 1 mm to 20 mm.

15. The electrode assembly according to claim 7, wherein: In the second direction, the eleventh distance from the first side to the fifth side is less than the twelfth distance from the second side to the sixth side.

16. The electrode assembly according to claim 7, wherein, In the second direction, the distance between the first side and the fifth side is 1 mm to 30 mm, and the distance between the second side and the sixth side is 1 mm to 20 mm.

17. The electrode assembly according to claim 7, wherein, In the second direction, the distance between the first end and the second end is 10 mm to 40 mm; The distance between the first side and the second side is 10mm to 40mm.

18. The electrode assembly according to claim 1 or 7, wherein, The first conductive portion further includes a seventh region separate from the first region, the seventh region being located on the side of the first region away from the second region.

19. The electrode assembly according to claim 7, wherein, The second conductive portion further includes an eighth region that is separate from the fourth region, the eighth region being located on the side of the fourth region away from the fifth region.

20. The electrode assembly according to claim 1 or 7, wherein, The first conductive part is the positive electrode.

21. The electrode assembly according to claim 1 or 7, wherein, The second conductive part is the negative electrode.

22. The electrode assembly according to claim 7, wherein, The first conductive portion is wound around a first axis and includes multiple layers of the first region along the first direction. The second conductive portion is wound around the first axis and includes multiple layers of the fourth region along the first direction. The first metal portion is connected to the outermost first region along the first direction, and / or the second metal portion is connected to the outermost fourth region along the first direction.

23. A battery, wherein, The battery includes a housing and an electrode assembly as described in any one of claims 1 to 22, the electrode assembly being disposed within the housing.

24. The battery according to claim 23, wherein, The material of the shell includes metal.

25. The battery according to claim 23 or 24, wherein, The battery is a wound battery.

26. An electronic device, wherein, The electronic device includes the battery according to any one of claims 23 to 25.

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